Method of controlling the duration of an endpoint polishing process in a multistage polishing process

A method of polishing performed on a polishing tool comprised of at least first and second platens, the method comprising:

• providing a wafer having a layer of copper formed thereabove;
• performing a timed polishing operation on said layer of copper at said first platen to remove a majority of said layer of copper;
• performing an endpoint polishing operation on said layer of copper at said second platen to remove substantially all of said layer of copper remaining after said timed polishing operation is performed at said first platen;
• determining a duration of said endpoint polishing operation performed on said layer of copper at said second platen;
• and
• modifying, based upon a variance between said determined duration of said endpoint polishing operation and a target value for said duration of said endpoint polishing operation, a duration of a timed polishing operation to be performed on a subsequently processed layer of copper at said first platen.

A method of polishing performed on a polishing tool comprised of at least first and second platens, the method comprising:

• providing a wafer having a layer of copper formed thereabove;
• performing a timed polishing operation on said layer of copper at said first platen to remove between 50-80% of said layer of copper;
• performing an endpoint polishing operation on said layer of copper at said second platen to remove substantially all of said copper layer remaining after said timed polishing operation is performed at said first platen;
• determining a duration of said endpoint polishing operation performed on said layer of copper at said second platen;
• and
• modifying, based upon a variance between said determined duration of said endpoint polishing operation and a target value for said duration of said endpoint polishing operation, a duration of a timed polishing operation to be performed on a subsequently processed layer of copper at said first platen.

A method of polishing performed on a polishing tool, the method comprising:

• providing a wafer having a layer of copper formed thereabove;
• performing a first polishing operation on said layer of copper to remove at least some of said layer of copper;
• performing an endpoint polishing operation on said wafer to remove substantially all of said layer of copper remaining after said first polishing operation;
• determining a duration of said endpoint polishing operation performed on said layer of copper;
• and
• determining, based upon a comparison between the determined duration of said endpoint polishing operation and a target value for said endpoint polishing operation, a duration of a first polishing process to be performed on a subsequently processed layer of copper.